Multicenter standardized 18F-FDG PET diagnosis of mild cognitive impairment, Alzheimer's disease, and other dementias.

This multicenter study examined (18)F-FDG PET measures in the differential diagnosis of Alzheimer's disease (AD), frontotemporal dementia (FTD), and dementia with Lewy bodies (DLB) from normal aging and from each other and the relation of disease-specific patterns to mild cognitive impairment (MCI). METHODS: We examined the (18)F-FDG PET scans of 548 subjects, including 110 healthy elderly individuals ("normals" or NLs), 114 MCI, 199 AD, 98 FTD, and 27 DLB patients, collected at 7 participating centers. Individual PET scans were Z scored using automated voxel-based comparison with generation of disease-specific patterns of cortical and hippocampal (18)F-FDG uptake that were then applied to characterize MCI. RESULTS: Standardized disease-specific PET patterns were developed that correctly classified 95% AD, 92% DLB, 94% FTD, and 94% NL. MCI patients showed primarily posterior cingulate cortex and hippocampal hypometabolism (81%), whereas neocortical abnormalities varied according to neuropsychological profiles. An AD PET pattern was observed in 79% MCI with deficits in multiple cognitive domains and 31% amnesic MCI. (18)F-FDG PET heterogeneity in MCI with nonmemory deficits ranged from absent hypometabolism to FTD and DLB PET patterns. CONCLUSION: Standardized automated analysis of (18)F-FDG PET scans may provide an objective and sensitive support to the clinical diagnosis in early dementia.     

Visual assessment versus quantitative assessment of 11C-PIB PET and 18F-FDG PET for detection of Alzheimer's disease.

Amyloid-beta (Abeta) imaging with N-methyl-(11)C-2-(4'-methylamino-phenyl)-6-hydroxy-benzothiazole ((11)C-6-OH-BTA-1; also known as (11)C-PIB) shows a robust increase in cortical binding in Alzheimer's disease (AD). The aim of this study was to explore the clinical potential of Abeta imaging for the diagnosis of AD by comparison of the accuracy of visual reading of (11)C-PIB images with quantitative analysis and (18)F-FDG. METHODS: Fifteen AD patients (age, 71.1 +/- 11.3 y [mean +/- SD]; mini-mental state examination [MMSE], 18.9 +/- 9.3 [mean +/- SD]) and 25 healthy control (HC) subjects (age, 71.9 +/- 6.82 y; MMSE >or= 28) underwent 90-min dynamic (11)C-PIB PET and 20-min static (18)F-FDG PET. (11)C-PIB images, generated from data acquired between 40 and 70 min after injection, and (18)F-FDG images were rated separately by 2 readers as normal, possible AD, or probable AD. Quantitative analyses used the distribution volume ratio (DVR) of frontal cortex, parietotemporal cortex, posterior cingulate, and caudate nucleus for (11)C-PIB and standardized uptake value ratio (SUVR) of parietotemporal cortex and posterior cingulate for (18)F-FDG, using cerebellar cortex as the reference region. Receiver-operating-characteristic (ROC) analysis was performed to compare the accuracy of quantitative measures. To determine the effect of age on diagnostic accuracy, the median age of the AD subjects (74 y) was chosen to separate the cohort into younger (64.4 +/- 5.8 y) and older (78.6 +/- 4.1 y) groups. RESULTS: Visual agreement between readers was excellent for (11)C-PIB (kappa = 0.90) and good for (18)F-FDG (kappa = 0.56). (11)C-PIB was more accurate than (18)F-FDG both on visual reading (accuracy, 90% vs. 70%, P = 0.05) and ROC analysis (95% vs. 83%, P = 0.02). Accuracy declined more with (18)F-FDG than with (11)C-PIB in the older group. CONCLUSION: Visual analysis of (11)C-PIB images appears more accurate than visual reading of (18)F-FDG for identification of AD and has accuracy similar to quantitative analysis of a 90-min dynamic scan. The accuracy of (11)C-PIB PET is limited by cortical binding in some healthy elderly subjects, consistent with postmortem studies of cerebral Abeta. Longitudinal follow-up is required to determine if this represents detection of preclinical AD.     

18F-FDG PET detection of colonic adenomas.

The adenomatous polyp of the colon is clinically important as a precursor of colonic cancer. The aim of this preliminary study was to evaluate the potential usefulness of (18)F-FDG PET for detecting adenomatous polyps of the colon. METHODS: We performed a retrospective study of 110 subjects who underwent both PET study and total colonoscopy. On nonattenuation-corrected PET images, focal distinct FDG accumulation along the large intestine was considered a positive finding, and the PET results were compared with colonoscopic findings. Histology and adenoma size were determined by polypectomy. RESULTS: Fifty-nine adenomatous polyps, 5-30 mm in size, were found in 30 subjects by total colonoscopy. PET findings were positive for 14 of the 59 adenomas (24%). The positivity rate for PET images rose with the increase in size of the adenomas; it was 90% in adenomas (9/10) that were > or =13 mm. The overall false-positive rate was 5.5% (6/110 subjects). CONCLUSION: Increased glucose metabolism is observed in colonic adenomas, and detectability with PET increases with the increase in adenoma size. Adenomas are premalignant lesions, and it is important to realize that colonic adenomas may be found incidentally during an FDG PET study.     

Cerebral metabolic changes accompanying conversion of mild cognitive impairment into Alzheimer's disease: a PET follow-up study

A high percentage of patients with mild cognitive impairment (MCI) develop clinical dementia of the Alzheimer type (AD) within 1 year. The aim of this longitudinal study was to identify characteristic patterns of cerebral metabolism at baseline in patients converting from MCI to AD, and to evaluate the changes in these patterns over time. Baseline and follow-up examinations after 1 year were performed in 22 MCI patients (12 males, 10 females, aged 69.8+/-5.8 years); these examinations included neuropsychological testing, structural cranial magnetic resonance imaging and fluorine-18 fluorodeoxyglucose positron emission tomography (PET) evaluation of relative cerebral glucose metabolic rate (rCMRglc). Individual PET scans were stereotactically normalised with NEUROSTAT software (Univ. of Michigan, Ann Arbor, USA). Subsequently, statistical comparison of PET data with an age-matched healthy control population and between patient subgroups was performed using SPM 99 (Wellcome Dept. of Neuroimaging Sciences, London, UK). After 1 year, eight patients (36%) had developed probable AD (referred to as MCI(AD)), whereas 12 (55%) were still classified as having stable MCI (referred to as MCI(MCI)). Compared with the healthy control group, a reduced rCMRglc in AD-typical regions, including the temporoparietal and posterior cingulate cortex, was detected at baseline in patients with MCI(AD). Abnormalities in the posterior cingulate cortex reached significance even in comparison with the MCI(MCI) group. After 1 year, MCI(AD) patients demonstrated an additional bilateral reduction of rCMRglc in prefrontal areas, along with a further progression of the abnormalities in the parietal and posterior cingulate cortex. No such changes were observed in the MCI(MCI) group. In patients with MCI, characteristic cerebral metabolic differences can be delineated at the time of initial presentation, which helps to define prognostic subgroups. A newly emerging reduction of rCMRglc in prefrontal cortical areas is associated with the transition from MCI to AD.     

Imaging infection and inflammation in children with (18)F-FDG PET and (18)F-FDG PET/CT

The goal of this article is to delineate indications for (18)F-FDG PET/CT pertaining to inflammation in the pediatric population, with emphasis on those that have been described in the literature. The limitations of (18)F-FDG PET/CT in this type of evaluation are also described, and the importance of using as low a dose as feasible is discussed. After reading this article, the reader should be able to list several clinical situations in which (18)F-FDG PET/CT may be appropriate, describe some limitations of (18)F-FDG PET/CT, and explain why dose is particularly important in the pediatric population.     

Comparison of 18F-FDG PET and optimized voxel-based morphometry for detection of Alzheimer's disease: aging effect on diagnostic performance.

The aim of this study was to compare optimized voxel-based morphometry (VBM) and (18)F-FDG PET for discrimination between patients with Alzheimer's disease (AD) and healthy subjects in relation to age. METHODS: The study population consisted of 2 groups; the first group (27 AD patients and 40 control subjects) was used to determine the locations of significant abnormalities for both PET and VBM using statistical parametric mapping, and the second group (34 AD patients and 50 control subjects) was used to compare the diagnostic performance of PET and VBM. In the second group, a z-score map for PET or VBM of each subject was obtained by comparison with the mean and SD of PET or gray-matter MR images of the control subjects. Receiver-operating-characteristic (ROC) curve analysis was then performed to compare the diagnostic performance between PET and VBM. Furthermore, group 2 was divided into the early- and late-onset subgroups, and ROC analysis was performed for each subgroup. RESULTS: In the first group, VBM revealed a significant decrease in gray-matter concentration in the hippocampus complex in AD, whereas PET showed a significant reduction in (18)F-FDG uptake in the posterior cingulate and parietotemporal lobe. The diagnostic performance of PET (0.988 +/- 0.008; mean +/- SE), as measured by the area under the ROC curve, was higher than that of VBM with (0.782 +/- 0.059) or without (0.832 +/- 0.049) modulation. PET yielded a sensitivity, specificity, and overall accuracy of 100%, 92%, and 95%, respectively, whereas for VBM the sensitivity, specificity, and accuracy were 74%, 92%, and 85%. Modulation for the VBM did not improve these values (56%, 94%, and 79%, respectively). When the early- and late-onset subjects were analyzed separately, the superiority of (18)F-FDG PET was significant only in the early-onset subgroup. CONCLUSION: The present study indicates that the detection of metabolic alteration by (18)F-FDG PET yields a better diagnostic performance for the discrimination between AD patients and healthy control subjects than does the morphologic approach by VBM, particularly in the early-onset subjects.     

Assessment of disease activity in rheumatoid arthritis with (18)F-FDG PET.

The aim of this study was to assess synovitis by (18)F-FDG PET in an individual joint analysis and in a global analysis of rheumatoid arthritis (RA) disease activity and to compare (18)F-FDG PET parameters with clinical, biologic, and sonographic (US) rheumatoid parameters. METHODS: Three hundred fifty-six joints were assessed in 21 patients with active RA: the knees in all subjects and either wrists as well as metacarpophalangeal and proximal interphalangeal joints in 13 patients, or ankles and the first metatarsophalangeal joints in the remaining 8 patients. PET analysis consisted of a visual identification of (18)F-FDG uptake in the synovium and measurements of standardized uptake values (SUVs). Independent assessors performed the clinical and US examinations. RESULTS: PET positivity was found in 63% of joints, whereas 75%, 79%, and 56% were positive for swelling, tenderness, and US analysis, respectively. Both the rate of PET-positive joints and the SUV increased with the number of positive parameters present (swelling, tenderness, US positivity) and with the synovial thickness. The mean SUV was significantly higher in joints where a power Doppler signal was found. In a global PET analysis, the number of PET-positive joints and the cumulative SUV were significantly correlated with the swollen and tender joint counts, the patient and physician global assessments, the erythrocyte sedimentation rate and C-reactive protein serum levels, the disease activity score and the simplified disease activity index, the number of US-positive joints, and the cumulative synovial thickness. CONCLUSION: (18)F-FDG PET is a unique imaging technique that can assess the metabolic activity of synovitis and measure the disease activity in RA.     

^18F-AV45PET显像在轻微认知下降和轻度认知障碍患者中的应用

目的 探讨^18F-AV45 PET显像检测的轻微认知下降(SCD)和轻度认知障碍(MCI)患者脑β-淀粉样蛋白(Aβ)沉积与患者认知状态的关系.方法 将上海交通大学附属第六人民医院2018年12月至2019年3月间诊断为SCD或MCI,且在2周内行^18F-AV45 PET显像、脑MRI T1扫描和简易精神状态检查量表(MMSE)检查的24例患者纳入研究,前瞻性收集数据,其中男11例、女13例,年龄(63.2±7.6)岁;SCD 15例、MCI 9例.对^18F-AV45 PET图像进行目测分析(阳性、弱阳性、阴性);再基于MRI图像对PET图像进行预处理后进行半定量分析,选择8个感兴趣区(ROI):额叶、外侧顶叶、外侧颞叶、内侧颞叶、枕叶、基底神经节、后扣带回和楔前叶,以小脑灰质为参考区,计算Aβ沉积的标准摄取值比值(SUVR),并计算偏相关系数,分析不同脑区SUVR与MMSE的相关性.结果 24例患者中,PET显像示Aβ沉积阳性16例、弱阳性8例,各脑区SUVR范围为0.93~1.87,MMSE评分为(28.2±2.0)分.MMSE评分与额叶皮质(r=-0.432)、后扣带回(r=-0.434)和楔前叶(r=-0.418)的SUVR呈负相关(均P<0.05),余脑区的SUVR与MMSE的相关性均无统计学意义(r值:-0.412^-0.110,均P>0.05).结论 ^18F-AV45 PET显像能无创性检测脑Aβ沉积,并在一定程度上反映SCD和MCI患者的临床认知状态.     

Substitution of oral (18)F-FDG for intravenous (18)F-FDG in PET scanning

The aim of this study was to see whether oral administration of (18)F-FDG could be substituted-without significant loss of information-for intravenous injection of (18)F-FDG in patients with difficult intravenous access of any cause, such as that often seen in cancer patients after many cycles of chemotherapy. METHODS: PET after both oral and intravenous administration of (18)F-FDG was performed on 2 healthy volunteers and 7 patients. An interval of 48 h was maintained between the oral administration and the intravenous administration. All scans were visually analyzed. Semiquantitative analysis of specific areas was done by calculating standardized uptake values (SUVs). Scanning was performed 60 min after intravenous tracer administration and 90 min after oral tracer administration. RESULTS: All lesions seen after intravenous administration were visualized on the oral study as well. SUVs were lower on the oral study than on the intravenous study. CONCLUSION: Oral (18)F-FDG can successfully be substituted for intravenous (18)F-FDG in patients with difficult intravenous access. However, because of the large amount of (18)F-FDG retained in the gut, careful interpretation will be required when disease of the gastrointestinal tract is being evaluated.     

Whole-body (18)F-FDG PET identifies high-risk myeloma.

The purpose of this study was to evaluate the clinical utility of whole-body PET with (18)F-FDG in patients with multiple myeloma and related monoclonal diseases. METHODS: Between July 1, 1996, and July 2000, 98 (18)F-FDG PET scans were obtained for 66 patients, with 25 patients having 2 or more scans. The results were compared with routine clinical and staging information, including CT and MRI scans, as indicated. Of the 66 patients, 16 had previously untreated active myeloma, 14 had monoclonal gammopathy of undetermined significance (MGUS), 10 had disease in remission, and 26 had relapsing disease. RESULTS: Negative whole-body (18)F-FDG PET findings reliably predicted stable MGUS. Of the 14 MGUS patients with follow-up of 3-43+ mo, myeloma has developed in only 1 (7%), at 8 mo. Conversely, the 16 previously untreated patients with active myeloma all had focal or diffusely positive scan findings. Four (25%) of 16 previously untreated patients with positive (18)F-FDG PET findings had negative full radiologic surveys. Another 4 (25%) of 16 patients had focal extramedullary disease. This was confirmed by biopsy or other imaging techniques. Extramedullary uptake also occurred in 6 (23%) of 26 patients with relapse. This extramedullary uptake was a very poor prognostic factor both before treatment and at relapse. For example, median survival was 7 mo for patients with disease relapse. Persistent positive (18)F-FDG PET findings after induction therapy predicted early relapse. In 13 (81%) of 16 patients with relapsing disease, new sites of disease were identified. The (18)F-FDG PET results were especially helpful in identifying focal recurrent disease in patients with nonsecretory or hyposecretory disease amenable to local irradiation therapy, which was used in 6 patients. CONCLUSION: Whole-body (18)F-FDG PET provides important prognostic information, which is clinically useful and complementary to conventional methods of evaluating plasma cell disorders. (18)F-FDG PET is a unique tool for evaluation of nonsecretory myeloma. Residual or recurrent disease after therapy, especially extramedullary disease, is a poor prognostic factor.     

Whole-body (18)F-FDG PET improves the management of patients with small cell lung cancer.

The aim of this study was to evaluate the impact of whole-body (18)F-FDG PET on staging and managing patients with small cell lung cancer (SCLC). METHODS: The treatment records of 42 consecutive patients (27 men, 15 women; mean age, 62 y; age range, 45-83 y) with SCLC were reviewed. Whole-body (18)F-FDG PET was performed for initial staging in 24 patients and for restaging after chemotherapy or radiation treatment in 20 patients. Two patients of the initial staging group were restaged with PET after therapy. PET findings were correlated with clinical and radiologic findings (CT of the chest and abdomen, bone scan, and CT or MRI of the brain). The impact of PET on staging and management decisions was determined. RESULTS: For 12 of 42 patients (29%), PET results changed the patient's management. In 8 patients (19%), PET resulted in a change of radiation therapy because of the detection of previously unknown tumor foci. Adjuvant radiation therapy was cancelled in 3 patients. A change of radiation field and volume was necessary in 5 patients. In 1 patient, PET results excluded extensive disease, which permitted surgical resection of the tumor. Chemotherapy was discontinued in 2 patients and restarted in 1 patient on the basis of the PET findings. In 5 patients (12%), PET excluded malignancy as the suspicious lesions found with conventional cross-sectional imaging did not take up (18)F-FDG. CONCLUSION: The results of this study show that (18)F-FDG PET has a major impact on the management of patients with SCLC, influencing both the stage and the management in 29% of patients. PET is a highly valuable tool for accurate target definition of radiation treatment by reducing the probability of overlooking involved areas.     

Peritoneal carcinomatosis: role of (18)F-FDG PET.

Peritoneal carcinomatosis can be difficult to diagnose, as CT is insensitive, with peritoneal biopsy and lavage often subject to problems of sampling error. The aim of our study was to evaluate the role of (18)F-FDG PET in detecting peritoneal carcinomatosis in patients with stomach, ovarian, and adrenal cancer and mesothelioma and to compare the results with CT scans in the same patient group. Our secondary aim was to identify characteristic patterns of abdominal (18)F-FDG uptake in biopsy-proven peritoneal disease and to correlate these patterns with available histologic and anatomic findings after surgery and structural imaging. METHODS: The medical records of 88 patients with stomach (n = 48), ovarian (n = 13), and adrenal cancer (n = 6) and mesothelioma (n = 21) were reviewed for the presence of peritoneal tumor on (18)F-FDG PET and CT scans. The results were correlated with either contemporaneous peritoneal biopsy or ascitic aspirate or with radiographic or clinical follow-up if histology was negative or unavailable. Of 24 patients with suspected peritoneal tumor, 17 had biopsy-proven findings of peritoneal disease. RESULTS: Of the 24 patients with suspected peritoneal tumor, (18)F-FDG PET was positive in 14 patients, with 1 of these scans being false-positive, CT was positive in 10 patients, and either PET or CT was positive in 18 patients. This yielded sensitivities of 57% (13/23), 42% (10/23), and 78% (18/23), with uniformly high positive predictive values of 93% (13/14), 100% (10/10), and 95% (18/19), respectively. We identified 2 distinctly abnormal scintigraphic patterns of focal and uniform (18)F-FDG uptake corresponding to nodular and diffuse peritoneal disease on pathologic examination. CONCLUSION: (18)F-FDG PET adds to conventional imaging in the staging of peritoneal carcinomatosis. It is also a useful diagnostic tool when peritoneal biopsy is either unavailable or inappropriate. We have identified 2 distinct scintigraphic patterns that appear to predict the presence of either nodular or diffuse peritoneal pathology.     

Dynamic balance deficit and the neural network in Alzheimer's disease and mild cognitive impairment

BackgroundPatients with Alzheimer’s disease (AD) and mild cognitive impairment (MCI) exhibit balance deficits. Although only a few studies have evaluated the relationship between the brain images and balance indices. In this study, we measured balance indices, including the index of postural stability (IPS) and assessed the relationship between the brain images and their clinical motor and cognitive functional features.MethodsThe study included patients with MCI (N = 14) and patients with AD (N = 19). The primary outcome was IPS under a visual block condition and/or a proprioception block condition. In addition, 9 MCI and 8 AD patients underwent a 1.5-Tesla (1.5-T) Magnetic Resonance Imaging (MRI) scan, and the relationships between the MRI parameters and the balance indices were evaluated.ResultsThe IPS score was significantly lower in the AD group than the MCI group, but only under the closed eyes/hard surface condition. In terms of MRI, there was a significant positive correlation between the IPS and the regional betweenness centrality in the left hippocampal region.ConclusionsThe finding of a significantly lower IPS score under the closed eyes/hard surface condition in AD than in MCI cases suggests that the vestibular and/or proprioceptive systems were more severely impaired in AD than MCI cases. The results suggest that a dynamic balance disturbance due to deficits of the vestibular hippocampal pathway may be a useful marker for the diagnosis of MCI and detection of disease progression from MCI to AD.     

Noninvasive assessment of Crohn's disease intestinal lesions with (18)F-FDG PET/CT.

Pilot studies have shown good sensitivity and specificity for (18)F-FDG PET in detecting gastrointestinal lesions of Crohn's disease. The combination of (18)F-FDG PET with CT may further improve the localization and characterization of lesions with increased (18)F-FDG uptake. Our aim was to assess the use of (18)F-FDG PET/CT in evaluating the activity and location of Crohn's disease along the gastrointestinal tract. METHODS: After giving informed consent, 22 patients with Crohn's disease were prospectively studied. They underwent (18)F-FDG PET/CT, followed by ileocolonoscopy within 1 wk (mean, 2 d). The Crohn's disease activity index (CDAI) was calculated, and serum C-reactive protein (CRP) and fecal calprotectin were measured before endoscopy. The Crohn's disease endoscopy index of severity (CDEIS) was calculated during endoscopy. The global CDEIS score and endoscopic subscores for various ileocolonic segments were used for analysis. RESULTS: Globally, 95 intestinal and colonic segments in 22 patients were analyzed. (18)F-FDG PET/CT detected 35 of 48 endoscopically affected segments (sensitivity for the detection of endoscopic lesions, 72.9%). The sensitivity of (18)F-FDG PET/CT for the detection of severe endoscopic lesions (deep ulcers and strictures) was 100% (14/14). The global PET/CT score significantly correlated with CDEIS (r = 0.51; 95% confidence interval [CI], 0.09-0.77; P = 0.017), CDAI (r = 0.58; 95% CI, 0.17-0.80; P = 0.005), and CRP (r = 0.56; 95% CI, 0.19-0.81; P = 0.007). CONCLUSION: (18)F-FDG PET/CT was globally well correlated to the clinical, endoscopic, and biologic activity of Crohn's disease. Above all, this technique had a good sensitivity for the detection of intestinal and colonic segments with moderate to severe mucosal lesions. The potential impact of this promising tool on the global management of patients with Crohn's disease should be further evaluated in prospective studies.     

肺癌18F-FLT PET和18F-FDG PET的临床对比研究

目的 探讨18F-FLT PET在肺癌诊断和肿瘤增殖检测方面的应用价值.方法 对2005年9月-2008年10月解放军总医院收治的36例(男27例,女9例,年龄38～74岁)胸部CT疑似肺癌患者进行18F-FLT PET扫描,对同期收治的42例(男29例,女13例,年龄37～75岁)胸部CT疑似肺癌患者进行18F-FD...     

Functional interactions of the entorhinal cortex: an 18F-FDG PET study on normal aging and Alzheimer's disease.

Alzheimer's disease (AD) is a brain disorder characterized by reduced cerebral glucose metabolism (CMRgl) in several cortical regions. Evidence from neuropathology studies, animal models of AD, and (18)F-FDG PET studies on cognitive impairment suggest that disrupted connections with the entorhinal cortex (EC) could be implicated in the emergence of the cortical hypometabolism. This (18)F-FDG PET study assessed the functional interactions-that is, the intercorrelations between the EC and the whole brain in vivo-in normal aging and AD. METHODS: Eighty-seven consecutive clinical AD patients underwent (18)F-FDG PET scanning at rest. Thirty-five sex- and age-matched healthy elderly subjects were studied as controls (NC). A voxel-based correlation analysis was performed with statistical parametric mapping to assess significant correlations between relative CMRgl (rCMRgl) in the EC and the rest of the brain, for NC and AD patients. Results were considered significant at P < 0.001. RESULTS: The pattern of EC functional interactions varies between normal aging and AD patients. In NC, the left and right EC were bilaterally correlated with several cortical and limbic regions, in accord with the major anatomic pathways identified in nonhuman primates. Alternatively, in AD patients, the EC correlations with the contralateral hemisphere were entirely lost, whereas those within the ipsilateral hemisphere were preserved only with the inferior temporooccipital (T-O) areas. CONCLUSION: This (18)F-FDG PET correlation study indicates that AD-related processes lead to an altered functional relationship between the EC and several cortical and limbic regions, with respect to normal aging. Our results suggest that the assessment of coupled rCMRgl reductions between the EC and the ipsilateral T-O cortex, besides the typical pattern of cortical reduction, could increase (18)F-FDG PET diagnostic sensitivity and further motivate its inclusion in the clinical assessment of AD.     

~(18)F-FDGPET显像在肿瘤学中的应用

从 (氟代脱氧葡萄糖 )在正常人体内的分布角度考虑 ,使用 PET进行 1 8F- FDG显像可应用于脑肿瘤、结直肠癌、淋巴瘤、黑色素瘤、肺癌以及头颈部肿瘤等。美国核医学会 (SNM)已报道 1 8F- FDG显像在原发性脑肿瘤、乳腺癌、骨肿瘤、肺癌、前列腺癌、黑色素瘤及淋巴瘤等中的应用。初步结果表明 ,葡萄糖代谢在坏死型及持续型生长肿瘤中有明显差别 ,当肿瘤局部 FDG利用减低 ,提示治疗后有明显效果。本文简要综述 1 8F- FDG PET显像在乳腺癌、胰腺癌、肝细胞癌、肌肉骨骼肿瘤、内分泌肿瘤、生殖泌尿道肿瘤和胃食道肿瘤中的应用。     

Forced diuresis improves the diagnostic accuracy of 18F-FDG PET in abdominopelvic malignancies.

Our aim was to evaluate the role of forced diuresis in improving the diagnostic accuracy of abdominopelvic (18)F-FDG PET. METHODS: Thirty-two patients were enrolled. Besides the presence of known intravesical tumors or undefined renal lesions on the initial PET scan, the inclusion criterion was the appearance of indeterminate or equivocal (18)F-FDG foci that extended along the course of the urinary tract and could not confidently be separated from urinary activity. For each patient, a second abdominopelvic PET study was performed after intravenous injection of 0.5 mg of furosemide per kilogram of body weight (maximum, 40 mg) coupled with parenteral infusion of physiologic saline. RESULTS: Forced diuresis coupled with parenteral hydration eliminated any significant (18)F-FDG activity from the lower urinary tract in 31 (97%) of 32 patients after the bladder had been voided 3 successive times. Twelve intravesical lesions were visualized with outstanding clarity, whereas radiologic suspicion of locally recurrent bladder tumors was ruled out in 3 patients. Among 14 indeterminate or equivocal extravesical foci, 7 were deemed of no clinical value because they disappeared after furosemide challenge, whereas 7 persisting foci were proven to be true-positive PET findings. The performance of (18)F-FDG PET in characterizing 3 renal-space-occupying lesions could not be improved by our protocol. CONCLUSION: Furosemide challenge has the potential to noninvasively resolve the inherent (18)F-FDG contrast handicap in the lower urinary tract.